TSQL Distinct,以及OrderBy和WHERE

Question

我有以下SQL语句示例:

SELECT DISTINCT [CommentNdx]
      ,[CommentsText]
      ,[DateTimeAdded]
  FROM [dbo].[CommentTable]
ORDER BY [dbo].[CommentTable].DateTimeStart DESC
WHERE [CommentsText] = 'Hello World'

我一直收到错误,Incorrect syntax near the keyword 'WHERE'. 我知道语法不正确,但我不确定应该如何格式化.任何帮助表示赞赏.

更新:

我的错误,我的意思是日期时间开始应该是datetimeadded.修正了语法.

SELECT DISTINCT [TestCommentNdx]
      ,[TestID]
      ,[CommentsText]
      ,[DateTimeAdded]
      ,[OperatorNdx]
  FROM [PTDB].[dbo].[TestsComments]
WHERE [TestID] = 1174411854
ORDER BY [PTDB].[dbo].[TestsComments].[DateTimeAdded] DESC

更新2:

非常感谢大家,最后一件事,如果select语句中有连接,它会有所作为吗？我有一个很长的查询连接,当我尝试使用DISTINCT时,我得到了ORDER BY items must appear in the select list if SELECT DISTINCT is specified.

Answer 1

WHERE需要在ORDER BY之前.此外,除非它包含在SELECT语句中,否则您将无法按DateTimeStart排序.